Compressible piston ring



L. c. BURNS CQMPRESSIBLE PISTON RING March 18, 1958 Filed Nov. 1. 1954 QBeO NVENTOR.

urns

Affom/j Unite cornrnnssmrn PisToN RING Leo C. Burns, Mnskegon, Mich assignor to Sealed Power Corporation, Muskegon, Mich, a corporation of Michigan This invention relates to a compressible piston ring member which in the form illustratedmay be used as a combined spacer and expander having inherent force Within itself when circumferentially compressed to press spaced thin metallic rails outward, such rails and the novel ring member of my invention being installed in the groove of a piston, the outer edges of the rails being held with pressure force against the wall of a cylinder in which the piston in installed.

While the embodiment in which the invention is shown is for use as an expander and spacer for steel rails, substantially the same structure may be used as a circumferentially compressible piston ring by reversing the position of the upper and lower side of the ring segments and removing the ledges which are used for the inner curved edges of the rails to bear against.

It is an object of the present invention to provide a novel, simple and inexpensive and practical and useful, circumferentially compressible piston ring member which has very full and complete ventilation for the passage of lubricating oil therethrough and which, used as a support, expander and spacer for fiat circular rails in a composite piston ring, will not only press the rings outward uniformly but will cause them to engage against the opposed sides of the piston ring with sealing pressure against the passage of oil between the rails and the sides of the ring groove.

An understanding of [the invention may be had from the following description taken in connection with the accompanying drawing, in which,

Fig. 1 is an elevation showing the first steps of procedure in stamping the tied together spacer segments of the ring member from a length of thin metallic ribbon stock.

Fig. 2 is a section substantially on the plane of line 22 of Fig. 1.

Fig. 3 is a fragmentary elevation of a succeeding step in the formation of a ring member.

Fig. 4 is a transverse section on the plane or line 4-4 of Fig. 3.

Fig. 5 is a fragmentary elevation of the ring member when completed, the several segments thereof being formed into U-shape.

Fig. 6 is a fragmentary section of the complete ring including rails and spacer member between them, and

Fig. 7 is a transverse section through a completed piston ring in which my invention is used as a spacer installed in the groove of a piston with the rails bearing against the Wall of a cylinder, said piston and cylinder being fragmentarily shown in section, the plane of the section being substantially on the line 7-7 of Fig. 6.

Like reference characters refer to like parts in the different figures of the drawings, and all sections are taken looking in the direction of the arrows associated with the section lines.

The ring member of my invention is made of thin metallic ribbon stock of uniform preselected width, as indicated at l in Fig. 1. Such ribbon stock is stamped rates. Patent and cut to provide opposed spacing slots 2, aligned transeach edge of the ribbon 1. Between the slots rectangular sections 3 having a length equal'to the width of the ribbon stock 1 are connected by straight ties 4, the length of which is equal to the width of slots 2. Each of the rectangular sections 3 has a relatively long and wide opening 5 cut therefrom symmetrically located with re-* spect to the central longitudinal axis of the ribbon 1,

there being left at each side of each opening 5 relatively narrow stripsiuz in the sections 3, the adjacent narrow strips 3a of any two successive sections 3 .beiug'integrally connected. at their middle points by the ties or1strutsr4;

The ends of the'openings 5 arerclosed. The end portions of .the sections 3 beyond the closed ends of theiopenings, 5'when the ring member is to be used as a spacer and expander are bent in short lips or ledges 6 both to one side of the sections 3 as shown in Figs. 3 and 4, at an angle somewhat greater than a right angle to the planes of said sections.

A length of the ribbon stock sufficient to provide a piston ring member is thus formed and each of the sections 3 are shaped into U-shaped or channel segments having, as shown in Fig. 7, upper and lower flanges 3, upwardly and downwardly extending ledges 6 at the inner edges of the flanges and horizontal ties or struts 4 connecting the webs between the flanges of the segments. Such ring member is shaped into circular form with the ends of the length of material brought together in abutting relationship.

Used as an expander and spacer as illustrated, it is assembled with two thin parted metallic rails 7, usually of steel, one above and one below the expander and spacer. The three-part piston ring thus provided is adapted to be installed in a piston ring groove 8 of a piston 9 within the wall of a cylinder 10. The abutting ends of the ring member shown at 11 in Fig. 6 are brought together and the ring member is circumferentially compressed when thus installed in a piston in a cylinder. The ring member in its free form is of larger circumference than it will be when it is circumferentially compressed, the ends at the parting 11 being brought together and the sides 3a of the segments or sections 3 bent or strained toward each other. By such circumferential contraction in length an expanding force is generated in the ring member which, transmitted through the ledges 6 to the inner edges of the rails 7, press them at their outer edges against the cylinder wall with a uniform continuous unit pressure. Because of the angular relation of the sides of the ledges 6, each being inclined at an acute angle to the vertical, a component of the expanding force pressure in an upward vertical direction on the upper rail 7 and in a downward vertical direction on the lower rail 7 causes such rails to snugly and sealingly press against the sides of the ring groove 8. It is apparent that lubricating oil scraped from the inner Walls of the cylinder 19 by the rails is directed inwardly through the large ventilating openings left by the openings at 5 to the bottom of the ring groove 8 from which it drains through to the interior of the piston.

By reversing the bending of the sections 3 so that they extend outwardly with the ties 4 located inwardly in the piston ring groove 8 and eliminating the ledges 6, a circumferentially contractible piston ring is provided which having a proper axial width may be installed singly in the piston groove 8. The novel structure described is simply and easily manufactured at low cost. Various modifications in the detail of the form of the segments 3, the width of the slots 2, the widening of the sections 3 at their outer ends by narrowing the slots 2 at the Patented Mar. 18', 1958' and-integrallyconnecting successive adjacent segments to said strut located generally midway between the ends of said segments, each of said segments having an elongated relatively Wide opening therethrough extending lengthwise thereof from adjacent one end to adjacent the other end of each segment, said openings having sides generally parallel to the longitudinal edges of said segments, and said sides of each segment yieldingly resisting strain thereof toward each other.

7 2. A- piston ring member as defined in claim 1, each of said segments, at its free end having an outwardly extending narrow width ledge, integral therewith.

3. A circular, parted piston ring member comprising a succession of spaced, thin metal, channel shaped seg- 4- ments having upper and lower flanges and integral webs at right angles to said flanges connecting said flanges at one end thereof and short,- straight, substantially rigid struts located generally at right angles to the length and generally midway between the end of said webs extending between and integrally connected with the adjacent edges of successive Webs, each of said segments having an elongated opening lengthwise of the web thereof and extending into said flanges toward but short of the free ends ill thereof, there being provided resistingly yielding strips in said webs and flanges of said segments between the sides of said openings and the longitudinal edges thereof.

References Cited in the file of this patent UNITED STATES PATENTS 2,220,947 Paton Nov; 12, 1940 2,293,699 Engelhardt Aug. 25, 1942 2,303,798 Solenberger Dec. 1, 1942 2,635,022 Shirk' Apr. 14, 1953 2,695,825

Estey Nov. 30, 1954 

